Wound healing and repair Flashcards
What are parenchyma?
organ specific cells related to the function of the tissue
What would be the parenchyma of the kdineys?
Epithelial tissue (renal tubes)
What would be the parenchyma of the heart?
Muscle tissue (cardiac muscle cells)
What are stromal cells?
Stromal cells are connective tissue cells of any organ. They are cells that support the function of the parenchymal cells of that organ.
Provides the structure, mechanical and nutritional support to the organ
What types of connective tissue do joint capsules, tendons and ligaments have?
Dense irregular connective tissue – dense woven network of collagen and fibers in a viscous matrix
What types of connective tissue do haemopoietic and lymphatic tissue have?
Loose connective tissue – contains numerous cells, loose fiber arrangement in a viscous matrix
What is the parenchyma of fibrous connective tissue?
Tenocytes
What is a wound?
Injury/ trauma to tissues
Disruption of the function and structure of tissue
What is healing?
Process of returning to health
Restoration of structure and function of injured/diseased tissues
What are the main stages of Wound healing?
Haemostasis, Inflammatory, proliferative and remodelling
How long is each stage of wound healing?
Haemostasis <24hrs
Inflammatory 0-4 days
proliferative 1 - 14 days
remodelling 21 days - years
During which phase of wound healing, does angiogenesis occur?
Proliferative phase - angiogenesis, epithelialisation, contraction and fibrous tissue formation.
During which phase of wound healing, do platelets, macrophages and neutrophils come in?
Inflammatory phase - control bleeding, prevent infection, inflammation
How does the haemostasis phase work?
Wound closed by clotting (coagulation process)
Platelets and fibrin adhere to site
Formation of a thrombus
What happens during the remodelling process of wound healing?
Maturation phase
Collagen is remodeled and becomes re-aligned
Injured sites tend to be weaker than normal sites (80% tensile strength)
How does a tissue heal if there is a mild, superficial injury?
regeneration
How does a tissue heal if there is a severe injury?
Scar formation
What are labile tissue? give examples.
continuously proliferating in order to replace dead or sloughed-off cells
Skin, gastrointestinal, salivary glad tissue
What are stable tissue? give examples.
cells that normally exist in a non-dividing state but may enter the cell cycle in response to certain stimuli, such as cell injury
Parenchymal cells of the liver, kidney and pancreas
What are permanent tissue? give examples.
non-dividing cells, leads to scar formation
cardiac and skeletal
Name the growth factors mainly involved in regeneration.
VEGF, PDGJ, TGF-beta
What are growth factors in regeneration, mainly produced by?
Macrophages and lymphocytes - as part of inflammatory process.
Parenchymal and stomal cells - produce growth factors in response to injury.
What is the function of VEGF?
Angiogenesis
Does angiogenesis involve sprouting of new vessels from existing ones? and what are pericytes?
Angiogenesis involves sprouting of new vessels from existing ones – involves Endothelial cell proliferation and migration
Promoted by VEGF
Critical in the site the site of injury – development of collateral circulations at sites if ischemia